Waterproof sheet and process of making same



Patented Dec. 3, 1929 UNITED STATES LESTER KIRSO'HBRAUN, OF LEONIA, NEW JERSEY WATERPROOF SHEET AN D PROCESS OF MAKING SAME No Drawing. Gontinuation or application Serial No. 404,014, filed August 16, 1920. This application filed July 19, 1928. Serial No. 294,043.

This application is a continuation of my co-pending application, Serial No. 404,014,

filed August 16, 1920.

This invention relates to improvements in waterproof sheets and process of making same, and refers more particularly to waterproof sheets preferably felted, made from cotton stalks or analogous paper making fibres,

saturated or impregnated with a waterproof ing agent.

Among the objects of the invention are to provide a waterproof sheet consisting of felted cotton stalks or analogous paper making fibres which, simultaneously with-the felting operation, are im regnated or saturated with a waterproo ing agent, as for example, rubber or asphalt, or combinations thereof.

The invention may be carried out as follows: I preferably take rubber and flux it with a bituminous material, such as asphalt or coal tar pitch, on calender rolls, in the usual way.

I then gradually add this rubber compound while itis in a more or less heated plastic condition to a relativelyvstifi paste of colloidal clay and water, the latter being in a heated condition, as for example, 180 F. The rubber compound is added to the paste in the well known types of kneading or mastieating machines, so as to permit the rubber compound to become gradually dispersed in very small particles in the aqueous paste.

This mixture is then thinned with the water and forms a non-adhesive emulsified matrix in which the rubber compound is dispersed through the water.

This emulsion is then mixed with pulp stock formed from cotton stalks or analogus paper making fibres and the mixture sufliciently thinned with water to permit of it readily flowing over a paper machine where the fibrous constituents thereof are felted.- As the water is removed the dispersed particles of the binder coalesce and unite to form a' continuous film throughout the felted sheet of fibrous stock. V If it is desired to vulcanize the sheet thus formed, a vulcanizing a ent, as sulphur, may be incorporated wit t e emulsion and the sheet is vulcanized as it passes over the drying rollsof the papermachine or over hot calender rolls.

The sheets thus formed may be used as rubber blankets, for waterproof packages, for

more heat resisting stock, as for example,

gaskets subjected to a high temperature.

I claim as myv invention:

1. A sheet consisting of a felted fibrous material, a coalesced rubber compound extending through the sheet and containing an argillaceous colloid.

2. A waterproof sheet comprising felted fibrous material and including coalesced rubber extending through t e sheet and containing an argillaceous co loid, possessing the characteristics of a product in which the fibrous constituents have been impregnated with the rubber simultaneously with the felting operation.

'3. A process of making a felted fibrous sheet consisting in making an emulsion including water, rubber and an ar 'llaceous colloidal emulsifying agent, mixing this with fibrous pulp, forming this mixture into sheets, removing the water and permitting the rubber to unite with the fibre.

4. A fibrous sheet comprising felted fibres having incorporated therewith a binder substance includin rubber and colloidal clay united with the bres.

5. A waterproof sheet, consisting of a felted fibrous material, a waterproof binder substance com rising a mixture of rubber and bituminous su stances containing a colloidal clay coalesced with the fibres.

6. A process of making a felted fibrous sheet comprising making an emulsion includin water, rubber and colloidalclay, mixing the with fibrous pulp, forming this mixture into sheets removing the water and permitting the rubber to unite with the fibre.

A waterproof sheet, consisting of a felted fibrous material, a waterproof binder substance comprising a mixture of rubber and bituminous substances containing an argilliferous emulsifying agent 'coa'lesoed with the fibres.

8. A process of making fibrous articles containing rubber consisting in plasticizingthe rubber by milling, dispersing the plasticized rubber with acolloid in an aqueous vehicle so as to form an emulsion capable 'of'being thinned with water, in thereafter mixing fibrous pulp with said emulsion, felting the mixture, removing the water andper'mitting the rubber to coalesce. I g

9. A process of making a fibrous; sheet containing rubber consisting in plasticizing the rubber by milling, and dispersing it with a colloid in an e ueous-vehicle so as to form an emulsion capab e-of being thinned with water, in then mixing fibrous pulp with'said emul sion, sheeting the mixture on a paper forming machine,..drying the sheet and permitting the rubber to coalesce.

'10. The process. of making a fibrous sheet containing rubber consisting in subjecting the said rubber to the action of calendering rolls, in then dispersing-the rubber with a colloid in an aqueous vehicle to produce an emulsion capable of being thinned with water,

in then mixing fibrous pulp with said emulsion, sheeting the mixture on a paper forming machine, drying the sheet and permittingthe rubber to coalesce.

. 11'. The process of making paper which.

consists in adding to paper pulp prior .to passing the pulp through a paper-making machine, a non-adhesive rubbencontaining' emulsion, mixing the rubber-containing emulsion with the pulp stock and passing the mixed stock through a paper making machine.

12. A process of making paper which consists in adding to the paper pulp a rubbercontaining emulsion, mixing the emulsion with the pulp stock, passing the mixed stock over a paper-making machine and introducing an agent to vulcanize the rubber contained in the resultin paper.

13. A waterproof s eet composed of cotton pound impregnating and securing together the'cotton stalk fibres.

14. A waterproof sheet composed of cotton stalk fibres and a rubber containing com-- .stalk fibres impregnated and secured tomixing the mass to thoroughly disperse the rubber throughout the pulp, passing the containing rubber, which consists in adding to fibrous pulp a rubber containin substance, mixing the mass to thoroughly isperse the rubber throughout the pulp, passing the mixed pulp and rubber through a papermaking machine, and in introducing and incorporating a vulcanizing agent with the mixture.

18. A process of making fibrous articles, which consists in adding to the fibrous pulp a" rubber containing emulsion, mixing the pulp and the emulsion to thoroughl distribute the emulsion throughout the pu p material, adding a vulcanizing agent, and passing the mass through a paper making machlne to ,form the resultant article.

19. The process of making pa or which consists in adding a rubber emu sion to a fibrous material possessing the characteristics of high porosity and composed of loosely matted long fibres, mixing the fibrous material and the rubber emulsion and in finally forming the resultant article by passing the mixture through a papermaking machine.

20. The process of felting fibrous articles comprising.the steps of forming a viscous paste of a fluid vehicle and an emulsifying agent, adding a rubber substance to the paste, thoroughly agitating the mixture to disperse small particles of the rubber compound through the vehicle, mixin the resultant emulsion with fibrous mater1al,and in then passing the mixture of rubber emulsion and fibrous material through a paper making machine to produce the resultant article.

21. The process of making waterproof. fibrous articles which comprises the steps of first forming a paste consisting of an emulsifying agent and a fluid vehicle, adding a rubber containing substance to the mixture, and agitating the same together to thoroughl disperse small particles of the rubber throng the fluid vehicle and obtain anon-adhesive emulsion matrix, I and in then mixing the emulsion with fibrous material and passing the mixture through a paper making machine to produce the resultant waterproof articles.

22. A process of maln'ng a waterproof sheet which comprises mixing with fibrous stock rulflaer .dispersed in finely divided particles in the form of a non-adhesive aqueous emulsion, sheeting the mixture on a paper. ma-

chine, and'removing the water to permitthe' rubber to unite with the fibers.

23. A process of making a' waterproof sheet which comprises mixing with fibrous stock rubber dispersed in finely divided particles in 4 the form of a non-adhesive aqueous emuls on, sheeting the mixture'on' a paper mechine, and removing the water to permit the dispersed particles of rubber to coalesce and mute to form a. continuous film about the fibers.

24. The herein described process, which comprises mixing in water, paper making stock and a non-adhesive. emulsion containing rubber Waterproofing material and an emulsifying agent, and forming on a paper making machine a sheet from said mixture.

In testimony whereof I afiix my signature LESTER KIRSCHBRAUN. 

